Watarase Keikoku Railway (Watetsu)
Well known by its nickname Watetsu, the Watarase Keikoku Railway is a local line that runs for about an hour and a half through Kiryu Station (in Kiryu) and Mato Station (in Nikko). It has gained popularity as a sightseeing train that allows you to enjoy the beauty of the gorge that runs along the Watarase River.
The train ride takes about an hour and a half, and you get to see some really beautiful scenery from your seat. In summer, I recommend taking the little train without glass windows from Mizunuma Station—you'll have a gorgeous view of the gorge on one side and an open-air hot spring on the other. It's a unique experience you can only have in Japan.